The Mini Exercise Balance Ball is a fantastic exercise tool to strengthen key muscles in the abdomen, enhance core health, improve endurance, flexibility, posture and balance whenused in rehabilitation, strengthening and toning exercise programs. Made of soft, low-odor, flexible, durable PVC. Anti-burst and non-slip 9 inch diameter ball is designed to remain elastic and squishy when fully inflated and is slightly textured to stay in place while performing yoga, pilates, or physical therapy exercises. Mini diameter makes the ball convenient to carry and store.